linux-kernel - [PATCH v2 08/26] MIPS: dma-default: Don't check hw

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Message-ID: <20160830172929.16948-9-paul.burton@imgtec.com>
Date:   Tue, 30 Aug 2016 18:29:11 +0100
From:   Paul Burton <paul.burton@...tec.com>
To:     <linux-mips@...ux-mips.org>, Ralf Baechle <ralf@...ux-mips.org>
CC:     Paul Burton <paul.burton@...tec.com>,
        Matt Redfearn <matt.redfearn@...tec.com>,
        Qais Yousef <qais.yousef@...tec.com>,
        <linux-kernel@...r.kernel.org>,
        Robin Murphy <robin.murphy@....com>,
        Krzysztof Kozlowski <k.kozlowski@...sung.com>,
        James Hogan <james.hogan@...tec.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Alex Smith <alex.smith@...tec.com>,
        Max Filippov <jcmvbkbc@...il.com>
Subject: [PATCH v2 08/26] MIPS: dma-default: Don't check hw_coherentio if device is non-coherent

There are no cases where plat_device_is_coherent() will return zero
whilst hw_coherentio is non-zero, and acting any differently in such a
case doesn't make much sense - if a device is non-coherent with the CPU
caches then access to memory "coherent" with DMA must be uncached. Clean
up the nonsensical case.

Signed-off-by: Paul Burton <paul.burton@...tec.com>
---

Changes in v2: None

 arch/mips/mm/dma-default.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/arch/mips/mm/dma-default.c b/arch/mips/mm/dma-default.c
index a9c1e94..6540355 100644
--- a/arch/mips/mm/dma-default.c
+++ b/arch/mips/mm/dma-default.c
@@ -161,8 +161,7 @@ static void *mips_dma_alloc_coherent(struct device *dev, size_t size,
 	*dma_handle = plat_map_dma_mem(dev, ret, size);
 	if (!plat_device_is_coherent(dev)) {
 		dma_cache_wback_inv((unsigned long) ret, size);
-		if (!hw_coherentio)
-			ret = UNCAC_ADDR(ret);
+		ret = UNCAC_ADDR(ret);
 	}
 
 	return ret;
@@ -190,7 +189,7 @@ static void mips_dma_free_coherent(struct device *dev, size_t size, void *vaddr,
 
 	plat_unmap_dma_mem(dev, dma_handle, size, DMA_BIDIRECTIONAL);
 
-	if (!plat_device_is_coherent(dev) && !hw_coherentio)
+	if (!plat_device_is_coherent(dev))
 		addr = CAC_ADDR(addr);
 
 	page = virt_to_page((void *) addr);
@@ -210,7 +209,7 @@ static int mips_dma_mmap(struct device *dev, struct vm_area_struct *vma,
 	unsigned long pfn;
 	int ret = -ENXIO;
 
-	if (!plat_device_is_coherent(dev) && !hw_coherentio)
+	if (!plat_device_is_coherent(dev))
 		addr = CAC_ADDR(addr);
 
 	pfn = page_to_pfn(virt_to_page((void *)addr));
-- 
2.9.3